Electric heater.



H. W. DENHARD.

ELECTRIC HEATER. APPLICIATION man OCT. 31. 1911.

1,143,578. Patented June 15, 1915.

2 SHEETS-SHEET l.

7&1.

H. W. DENHARD.

ELECTRIC HEATER.

APPLICIATION FILED 061331, 1911.

Patented June 15, 1915.

2 SHEETSSHEET 2- UNITED STAT S PATENT OFFICE.

.EABRY VT. DENHABD, OF SAN FRANCISCO,

CALIFORNIA. ASSIGNOB TO THE CUTLER- IHAMMER MFG. (19., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

ELECTRIC THEATER.

cient heater of rugged construction which unay be readily manufactured at small exuse. Other objects and advantages of the invention will hereinafter appear.

. .The accompanying drawings illustrate an embodiment of the invention.

in the views of these drawings: Fi ure 1 shows a side elevation of a heater. ig. 2 shows end .elevationof the same and the door mechanism. Fig. 3 shows a side elevation mi the heating element with a portion of the casing in section. Fig. 4 shows a transverse sectional view on the line H of Fig. 3. Figs. 5 and 6 show detail views of a modified form of heating conductor support? 4 l. have, for the purposes of illustration, shown, my improved heating device applied to use as an electric toaster (Of the portable type, wherein the heating element stands vertically upon a frame and is so arranged that the articles to be toasted may be placed on oppositev sides of the same and inclosed between the element and suitable doors.

In the form shown, the 'heating element is carried in a framed supported upon a base 2. Withinthis frame the heating ele ment is preferably mounted upon trans versely extending rods 3 which extend across the frame at the top and bottom of the same. These rods maybe secured to the frameat their ends by screws l or other suitable means. As illustrated in Fig. 3, this heating element may include a plurality of ventically extending insulating members 5 which are spaced from each other between thesides of the frame 1. In a preferred form, the ends of the outer members are held in .position, spaced from the sides of the frames by sleeves .6 which inolose a portion of the Specification of Letters Patent. Patented J n 15 1915 Application filed October 31,

1911. :Serial NrnBSZ-BQS.

shank of the screw .and -fit between the side of the frame and the members 5., as shown in. Fig.3. In order that the insulating vertical members li may fit upon the rods, their upper ondszare preferably notched as at 7 t0=permit them to fit snugly upon 'or around the .outer surface of the rod. If desired, a more perfect union may be provided by means of the uselof a suitable cementing compound. All of the members 5 are preferably provided with notches 8 between their lender the notches on one edge of the members being offset with respect to those on the other edge, so that a resistance material, preferably inthe form of a wire, may be wound back and forth across the members .5 :toiorm a Web.

In a :prefem'ed form, the resistance mate rial is in the form or a single length of Wire, one :end of which is brought in at the terminals :Qofthe device. As shown in Fig.

still 3, these terminal members-9 may assume the usual form are preferably located in :the base 2 and at oneend thereof. By pref erence the terminals are insulated from the base 2 by means oi an ins sing plate 10. This plate preferably is aided with a perforation l1 registering with perforation. 12 in the-top of the base-through which the l16$l7li1gr60lilll0l30f extends. In the .present form the end of the heating conductor is-brought upward from one of the wrrni male 9 through the rperforations 11 and 12, to :a tubing 13, preferably made of metal, which extends upward along the inner side 'of .the left band member .5, being'preferably provided with one flat surface so that it may rest snugly against the surface of this member. In a. preferred form, the ends of this tubing are slightly compressed or fiattened as at 14 and provided with perforatioms'so that the holding screws 4 may pass through the same. By preference, the sides of the flattened ends of the tube 13 are provided with projections which are bent around about the upper and lower ends of the members 5 .in order to hold the tubing and member together and through'the at .tachment Dlf the flattenedends'of the tubing to the rods, provides sturdy structure. At

points adjacent the flattened ends of thetubing 13, openmgsam formed, and through bers 5, being passed first upon one side of -one member and then upon the other side of the member. if desired, it may be slightly bent as still at the points where it passes through the notches 8 in order to hold it more snugly in place. As the condoctor is brought back and forth across the Elli till members 5, it is also preferably wound spirally and closer together so that the heat developed at the bottom is the greatest. When it reaches thebottom of the members 5, its lower end is preferably brought out through a suitable insulating tube 17, as shown in Fig. 3, to the other terminal memher 9. As illustrated in liigs. 3 and 4, the opposite outer member 5 is also preferably provided with a similar member 13 similarlysecured to provide a sturdy structure.

in Figs. 5-and 6 l have illustrated a modified form of support which maybe used to support the ends of the convolutiorfs of the heating conductor. In this construction the conductors may be carried on a vertically extending plate or strip 18 which extends substautially atright' angles to the side of the frame If desired, an L-shaped angle plate 19 may be fixed to the freme and serve as a support for the plate l8. lln a preferred form a plurality of eyeletsfld are seated in suitable openinss near the outer edge of the plate 18, as shown in 6. These eyelets are preferably formed of insulating material and if desired-the plate l8 may be formed of this material or a suitable insulating support may bev provided for the same. lln a preferred form, the eyelets 20 are so arranged that there is a space between the front well of the some and the front wall of the plate lid so that resistance material may he slipped over the protruding end of the eyelet and passed in'loops' lunch and forth across the device as shown in Fig. l. The ends of the convolutions they be twisted, as shown. in Fig. 6 and applied toe unitof the construction shown in Fig. :3. However, the strips may be wound successively from one wide of the unit to the'other in substantially parallel convolutions',asshown in Fig. 7.

The end members of the frame 1 are slightly enlarged at their lower enols so that a door may be s'wiveled or otherwise secured in the same" In Fig. 2 l: have'illu trated a preferred means of attaching, the doors. As shown in this construction, the doors are preferahly formed of'a bent piece of metal 21, preferably carrying a transversely extending swi vel rod The outer ends of the rod Q2are prefen'tblyi bent downward substantially sit-right angles as shown frame 1.

at 23 in Fig. 2, and they are again bent at right angles to form extensions 24, which extensions are arranged to move in verti- 4 cally extending slots 25 in the sides of the In order to limit the backward movement of the door and guide the door in its forward movement, the forward edge of the side frame may be bent overas at 26 (shown in Figs. 1 and 2) or an additional plate may be attached to the end of the frame. In a preferred form, this extension or plate extends at right angles to the end of the frame. In order to suitably space the door from the material tobe heated, or if desired to carry this material, the door may be provided upon its inner surface. with an ex' tension or flange 27 preferably adjacent to the point Where it is bent. Obviously the door may be provided with a suitable heat insulated handle 28, as illustrated.

When it is desired to close the doors equipped with this form of door mechanism, all that is necessary to do is to'raise the door to closing position. As the door is raised, the curved back of the same rides over the upper edge of the extension .216, the end of the rod 22 remains substantiallystationary in the slot. When, however, the door is brought almost to its closed position, the end 24 slides down in the slot. lln opening the door, all that is necessary to do is to draw the handle 28 outward, whereupon the door is swiveled about the rod 22. which in turn moves about a pivot in its slot and may be opened to any desired degree, remaining in that position as long as desired. With this improved construction the doors may be very readily and quickly operated and serve to inolose the articles to be heated to any desired degree.

lt is of course, obvious that the frame'l may he provided with a handle 29 at its top,

suitably insulated from the device so that the latter may be placed inany desired position. l n a preferred form the frame l is also provided with transversely extending extensions 30 on itstop, (shown in Fig. 2) which serve to prevent the heatfrom passinp: upward toorapidly from the device and deflect it upon the material to bezheated. lln order that the heating element may be suitablv protected and spaced from the articles to beheated. grid members 31 may be provided. Further, the base 2 may be provided with a suitable opening in its end through 1 which a connection plug may be connected to the terminal members 9.

By my improved construction l have provided an improved electric heating device of an exceedingly simple and rugged con- 1 struction, wherein a heating: unit of high efficiency is securely fixed within the frame in such a position as to permit it to readily radiate the heat generated bythe passage of theourrent through the wire. By my 1 improved arrangement ofthe wire the heat is also delivered in the proportion required. Further, the parts of the heating unit are effectually insulated from the frame, By the provision of my improved door mechanism, I have been able to provide a construction which is well adaptedto permit the doors to move readily within a large range and to hold the doors in any desired position. Further, my improved device is exceedingly easy to manipulate and may be readily used la an inexperienced ierson. Fu aroved nea "i i 1y inventi w;

its sp' l l hat I claim as new and desire to secure by Letters Patent is 2'- l. An electric resistance unit having a frame provided with end. members and a plurality of cross members, a resistance wire wound back and forth across said cross members from one end of the frame to th other, one of said cross members being hollow to form a conduit for the return of the resistance wire whereby the terminals of said wire are adjacent each other.

2. In an electricresistance unit, a plurality of supporting members, a plurality of connecting members, one of said members being hollow and an electric resistance material wound spirally on certain of said members in such a manner that the convolutions are closer together at the bottom of'th'eunit, a portion of said resistance i'naterial extending through said hollow member and being insulated therefrom.

8. In an electric resistance unit, a plurality of supporting members, a resistance material carried thereby, a hollow member extending between said supporting members and having flattened ends attached thereto and means for attaching said hollow member to one of said insulating strips.

4. In an electric resistance unit, a plurality of supporting members, an electric resistance material wound thereon, and a. hol-- low member extending between said supporting members and having its ends attached-thereto, said hollow member being provided with extensions bent over one of said insulating strips. 7

In combination, a support, a plurality of spaced supporting members carried thereby, a pluralityof insulating strips carried between said supporting members, an

electric resistance material wound thereon and a hollow member serving as a conduit for a portion of said resistance material, having one of its ends'attached to said supporting members and one of said insulating strips.

6. In an electric resistance unit, a plurality of spaced rods, a plurality of insulating strips carried between the same, a resistance ninrality of insulating strips extending between the same, a hollow member extending as between said supporting members and having its ends attached to the latter and a re sistance material wound on said insulating strips and having a portion extending through said hollow member insulated therefrom.

9.. In combination, a support, a plurality of spaced supporting members carried thereby, a plurality of insulating strips carried between said supporting members, an we electric resistance materia-lwound thereon a hollow member carried by said supporting members and serving as a conduit for a portion of said resistance material and terminal members'carried by said support adjacent the end of said hollow member.

10. In an electric heating device, a sup-.v port a plurality of supporting members carried thereby, a plurality of spaced insulating strips carried between said members, e

plurality "of hollow members carried between said supporting members and attached to the same to form a frame, and a resistance material wound upon said strips member carried in said first mentioned tubular member and serving as a conduit for one of the ends of said resistance material.

12. In an electric heating device, a frame including a plurality of spaced rods and a plurality of hollow members having flattened ends attached to said rods, a plurality of spaced insulating strips carried in said frame, an electric resistance material wound on said insulating strips and having; one end extending through said hollow member, and

an insulating tubular member carried in said first-mentioned tubnlar member for insulating said resistance material.

HARRY W. DENHARD.

Witnesses:

H. L. ROCKWELL, Geo. B. JONES. 

